A multimedia broadcast/multicast service in a mobile communication network is a service mode in which a path of service data is established in the existing radio communication network by multicast or broadcast technology to achieve a service mode of distributing a service from one point to multiple points. A Multimedia Broadcast/Multicast Service (MBMS) and evolved MBMS (eMBMS) defined in the radio communication standard organizations of 3rd Generation Partnership Project (3GPP) are such services. For a radio communication network defined by 3GPP, so far, the defined radio access technologies related to the MBMS and the eMBMS include a Universal Terrestrial Radio Access Network (UTRAN) and an Evolved Universal Terrestrial Radio Access Network (E-UTRAN).
Take the eMBMS for example, network architecture of a multimedia broadcast/multicast service mode defined by 3GPP is shown as FIG. 1. Wherein, a Broadcast/Multicast Service Center (BM-SC) is a service data source from which all the data are sent to other network nodes. An MBMS Gateway (MBMS GW) is a service data gateway for a core network of mobile communication; it is responsible for receiving all the MBMS data from service network elements and further transmitting them to the subsequent network nodes, which is called “transmitting to the downlink nodes” according to positions in the network diagram.
In order to establish the whole service path, before sending data, it is necessary to send relative signaling to all nodes in the downlink path from the service source to notify all nodes of the session identifier identifying the multicast address information of the service, addresses of all downlink nodes, Quality of Service (QoS), initiation time and a service area and other information. This signaling is defined as MBMS session starting signaling at present. Signaling at the end of service is MBMS session ending signaling used for releasing the path.
Information in the signaling is configured in the BM-SC (or a network management system). The BM-SC obtains these information and forms parameters of the session signaling when sends the signaling.
Please refer to FIG. 2 and FIG. 3 for definitions of session starting signaling and session ending signaling.
The eMBMS is taken for example in both FIG. 2 and FIG. 3 to describe methods for sending session starting messages and session ending messages.
As shown in FIG. 2, the existing eMBMS session starting procedure includes the following steps:
step 201: a BM-SC sends an MBMS session starting request message to each MBMS GW;
the MBMS session starting request message can include session parameters and address parameters. Wherein, the session parameters include QoS, an MBMS service area list, an MBMS session identifier, estimated session duration and a destination network indicator (MBMS xG indicator) and so on; the address parameters include a downlink node address list (including address of the MBMS GW and a downlink node list of the MBMS GW) and so on;
step 202: the MBMS GW saves parameter information included in the message and returns a session starting response message to the BM-SC;
step 203: the MBMS GW sends an MBMS session starting request message to an MME (Mobility Management Entity);
step 204: the MME saves the information included in the message and sends the session starting request message to an E-UTRAN;
step 205: the E-UTRAN determines whether there is any cell belong to the service area and returns a session starting response message;
step 206: After receiving all session starting response messages from the E-UTRAN side, the MME sends the session starting response messages to the MBMS GW;
when a data acquisition function of a Charging Data Recorder (CDR) is activated by the MBMS GW, after receiving the session starting response messages, the MBMS GW sends a charging start request message (e.g. ACR[Start]) to the network elements related to the charging;
step 207: Reserving radio resources and establishing service paths, and sending data.
As shown in FIG. 3, the existing eMBMS session ending procedure includes the following steps:
step 301: the BM-SC sends an MBMS session ending request message to the MBMS GW; the message includes a session identifier, a service identifier and a downlink node list and so on; the MBMS GW returns a session ending response message to the BM-SC and releases information related to the service and saved by itself;
step 302: the MBMS GW transmits an MBMS session ending request message to an MME that has received the session starting message before, the MME returns a session ending response message and releases information that is related to the service and saved by itself;
when the data acquisition function of the CDR is activated by the MBMS GW, after receiving the session ending response messages, the MBMS GW sends a charging stop request message (e.g. ACR[Stop]) to a Charging Data Function (CDF);
303: the MME transmits the MBMS session ending request message to the E-UTRAN, and the E-UTRAN returns a session ending response message;
304: radio resources are released.
Distribution of multimedia broadcast/multicast service is limited to a certain area range and expressed by conception of Service Area (SA). Each SA is expressed by a series of Service Area Identifiers (SA ID) and each SA ID defines a series of radio cells (e.g. cell ID), therefore the position range of one specific SA is substantially corresponding to radio cells. One multimedia broadcast/multicast service can have one or more SAs to define the range.
Due to limit of the SA, from service source to downlink paths of radio access devices (such as, base station) in multimedia broadcast/multicast service are also definite. Therefore, for one SA, addresses of all downlink nodes are also definite. It should be noted that it is a heavy burden for signaling to send so many downlink node addresses as the number of radio access devices is huge. Therefore, the final level of downlink node address is an address of the upper level of radio access device instead of the address of the radio access device. The upper level of radio access device broadcasts the session signaling to all the connected radio access devices, if the radio access device does not belong to this SA, the radio access device returns an error message; when it belongs to this SA, the radio access device returns a path establish success message.
Generally, area ranges of SAs are configured in radio access devices, that is, which cells of radio devices belong to which the SA is achieved by configuration of radio access devices. The BM-SC has no need to know in which cell one service is to be played specifically, it only needs to know the corresponding SA or SA list; therefore, the BM-SC has to configure corresponding SA for each service. And it also needs to configure the address list of all downlink nodes.
After introduction of the E-UTRAN, there is another type for radio access technology. Different radio access technology type means different radio transmission quality and further provides different service transmission capacity and user experience. Compared with the UTRAN and earlier GRPS/EDGE Radio Access Network (GERAN), the E-UTRAN has greater bandwidth and higher data transmission stability and adapts to higher movement speed; during early stage of construction, it can be used in access points to relieve the network congestion. In this way, different radio access technologies can be corresponding to different multimedia broadcast/multicast services or to a same service to achieve different service effects. A problem whether the radio access technology can be used as a distinguishing option of charging is caused.
Past MBMS charging of GPRS includes content-based charging and bearing-based charging. For bearing-based charging, charging vectors at present are time and flow of each service; and the charging unit is mainly in the BM-SC, namely, the service source. A Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN) also achieve the collection of some charging vectors.
The eMBMS based on IP has two modes, i.e. broadcast mode and enhanced broadcast mode, but it has no multicast mode for users. Establishment of data path (namely, establishment of bearing) employs IP multicast protocol. The MBMS GW as a logic entity is introduced in the eMBMS; the MBMS GW can be used independently or arranged in the MB-SC or jointly arranged with a Serving Gateway (SGW)/Packet Data Network Gateway (PGW). Bearing-based charging is mainly completed on the network elements of mobile core network such as the MBMS GW; when receiving the relevant charging trigger events (such as, a MBMS session starting response message or a time interval message), the MBMS GW sends a charging request message including a service type, a service identifier, a service area, time, a flow and other information to the relevant entities of charging network gateway, such as CDF.
Corresponding to the change of eMBMS network architecture, content-based charging has little change, but bearing-based charging has great change along with change of the network architecture. The prior art is disadvantaged in that the current MBMS services can be sent to different Radio Access Technology Types (RAT Types) such as the UTRAN and the E-UTRAN, different radio access technology types can provide different access capacities for MBMS services, therefore the MBMS services can have different effects due to different radio access technology typed, even some MBMS services only can be accessed under radio access technology type with higher access capacity, thus the demand for distinguishing radio access technology types in terms of application and charging of services (including charging users and service providers) is arisen. However, the current MBMS charging and application solution fails to propose any method for distinguishing radio access technology types. Besides, radio access technologies as well as corresponding relationships between radio access technologies and related service areas and downlink nodes are also not described in the related technical specifications.
Introduction of the E-UTRAN also makes cells have some changes. Cells of the E-UTRAN are different from cells of the UTRAN in terms of number, which makes service area SA have UTRAN and E-UTRAN attributes. That is, the attribute of radio access technology of the SA can be determined due to whether the cell list contained in SA belongs to the UTRAN or the E-UTRAN or both the UTRAN and the E-UTRAN. At present, there is no configuration about radio access attribute of the SA in respect of configuration of the SA.